1 /*
2 * common eBPF ELF operations.
3 *
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation;
11 * version 2.1 of the License (not later!)
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this program; if not, see <http://www.gnu.org/licenses>
20 */
21
22 #include <stdlib.h>
23 #include <memory.h>
24 #include <unistd.h>
25 #include <asm/unistd.h>
26 #include <linux/bpf.h>
27 #include "bpf.h"
28
29 /*
30 * When building perf, unistd.h is overridden. __NR_bpf is
31 * required to be defined explicitly.
32 */
33 #ifndef __NR_bpf
34 # if defined(__i386__)
35 # define __NR_bpf 357
36 # elif defined(__x86_64__)
37 # define __NR_bpf 321
38 # elif defined(__aarch64__)
39 # define __NR_bpf 280
40 # elif defined(__sparc__)
41 # define __NR_bpf 349
42 # elif defined(__s390__)
43 # define __NR_bpf 351
44 # elif defined(__arc__)
45 # define __NR_bpf 280
46 # else
47 # error __NR_bpf not defined. libbpf does not support your arch.
48 # endif
49 #endif
50
ptr_to_u64(const void * ptr)51 static inline __u64 ptr_to_u64(const void *ptr)
52 {
53 return (__u64) (unsigned long) ptr;
54 }
55
sys_bpf(enum bpf_cmd cmd,union bpf_attr * attr,unsigned int size)56 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
57 unsigned int size)
58 {
59 return syscall(__NR_bpf, cmd, attr, size);
60 }
61
bpf_create_map_node(enum bpf_map_type map_type,int key_size,int value_size,int max_entries,__u32 map_flags,int node)62 int bpf_create_map_node(enum bpf_map_type map_type, int key_size,
63 int value_size, int max_entries, __u32 map_flags,
64 int node)
65 {
66 union bpf_attr attr;
67
68 memset(&attr, '\0', sizeof(attr));
69
70 attr.map_type = map_type;
71 attr.key_size = key_size;
72 attr.value_size = value_size;
73 attr.max_entries = max_entries;
74 attr.map_flags = map_flags;
75 if (node >= 0) {
76 attr.map_flags |= BPF_F_NUMA_NODE;
77 attr.numa_node = node;
78 }
79
80 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
81 }
82
bpf_create_map(enum bpf_map_type map_type,int key_size,int value_size,int max_entries,__u32 map_flags)83 int bpf_create_map(enum bpf_map_type map_type, int key_size,
84 int value_size, int max_entries, __u32 map_flags)
85 {
86 return bpf_create_map_node(map_type, key_size, value_size,
87 max_entries, map_flags, -1);
88 }
89
bpf_create_map_in_map_node(enum bpf_map_type map_type,int key_size,int inner_map_fd,int max_entries,__u32 map_flags,int node)90 int bpf_create_map_in_map_node(enum bpf_map_type map_type, int key_size,
91 int inner_map_fd, int max_entries,
92 __u32 map_flags, int node)
93 {
94 union bpf_attr attr;
95
96 memset(&attr, '\0', sizeof(attr));
97
98 attr.map_type = map_type;
99 attr.key_size = key_size;
100 attr.value_size = 4;
101 attr.inner_map_fd = inner_map_fd;
102 attr.max_entries = max_entries;
103 attr.map_flags = map_flags;
104 if (node >= 0) {
105 attr.map_flags |= BPF_F_NUMA_NODE;
106 attr.numa_node = node;
107 }
108
109 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
110 }
111
bpf_create_map_in_map(enum bpf_map_type map_type,int key_size,int inner_map_fd,int max_entries,__u32 map_flags)112 int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,
113 int inner_map_fd, int max_entries, __u32 map_flags)
114 {
115 return bpf_create_map_in_map_node(map_type, key_size, inner_map_fd,
116 max_entries, map_flags, -1);
117 }
118
bpf_load_program(enum bpf_prog_type type,const struct bpf_insn * insns,size_t insns_cnt,const char * license,__u32 kern_version,char * log_buf,size_t log_buf_sz)119 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
120 size_t insns_cnt, const char *license,
121 __u32 kern_version, char *log_buf, size_t log_buf_sz)
122 {
123 int fd;
124 union bpf_attr attr;
125
126 bzero(&attr, sizeof(attr));
127 attr.prog_type = type;
128 attr.insn_cnt = (__u32)insns_cnt;
129 attr.insns = ptr_to_u64(insns);
130 attr.license = ptr_to_u64(license);
131 attr.log_buf = ptr_to_u64(NULL);
132 attr.log_size = 0;
133 attr.log_level = 0;
134 attr.kern_version = kern_version;
135
136 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
137 if (fd >= 0 || !log_buf || !log_buf_sz)
138 return fd;
139
140 /* Try again with log */
141 attr.log_buf = ptr_to_u64(log_buf);
142 attr.log_size = log_buf_sz;
143 attr.log_level = 1;
144 log_buf[0] = 0;
145 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
146 }
147
bpf_verify_program(enum bpf_prog_type type,const struct bpf_insn * insns,size_t insns_cnt,int strict_alignment,const char * license,__u32 kern_version,char * log_buf,size_t log_buf_sz,int log_level)148 int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
149 size_t insns_cnt, int strict_alignment,
150 const char *license, __u32 kern_version,
151 char *log_buf, size_t log_buf_sz, int log_level)
152 {
153 union bpf_attr attr;
154
155 bzero(&attr, sizeof(attr));
156 attr.prog_type = type;
157 attr.insn_cnt = (__u32)insns_cnt;
158 attr.insns = ptr_to_u64(insns);
159 attr.license = ptr_to_u64(license);
160 attr.log_buf = ptr_to_u64(log_buf);
161 attr.log_size = log_buf_sz;
162 attr.log_level = log_level;
163 log_buf[0] = 0;
164 attr.kern_version = kern_version;
165 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
166
167 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
168 }
169
bpf_map_update_elem(int fd,const void * key,const void * value,__u64 flags)170 int bpf_map_update_elem(int fd, const void *key, const void *value,
171 __u64 flags)
172 {
173 union bpf_attr attr;
174
175 bzero(&attr, sizeof(attr));
176 attr.map_fd = fd;
177 attr.key = ptr_to_u64(key);
178 attr.value = ptr_to_u64(value);
179 attr.flags = flags;
180
181 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
182 }
183
bpf_map_lookup_elem(int fd,const void * key,void * value)184 int bpf_map_lookup_elem(int fd, const void *key, void *value)
185 {
186 union bpf_attr attr;
187
188 bzero(&attr, sizeof(attr));
189 attr.map_fd = fd;
190 attr.key = ptr_to_u64(key);
191 attr.value = ptr_to_u64(value);
192
193 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
194 }
195
bpf_map_delete_elem(int fd,const void * key)196 int bpf_map_delete_elem(int fd, const void *key)
197 {
198 union bpf_attr attr;
199
200 bzero(&attr, sizeof(attr));
201 attr.map_fd = fd;
202 attr.key = ptr_to_u64(key);
203
204 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
205 }
206
bpf_map_get_next_key(int fd,const void * key,void * next_key)207 int bpf_map_get_next_key(int fd, const void *key, void *next_key)
208 {
209 union bpf_attr attr;
210
211 bzero(&attr, sizeof(attr));
212 attr.map_fd = fd;
213 attr.key = ptr_to_u64(key);
214 attr.next_key = ptr_to_u64(next_key);
215
216 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
217 }
218
bpf_obj_pin(int fd,const char * pathname)219 int bpf_obj_pin(int fd, const char *pathname)
220 {
221 union bpf_attr attr;
222
223 bzero(&attr, sizeof(attr));
224 attr.pathname = ptr_to_u64((void *)pathname);
225 attr.bpf_fd = fd;
226
227 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
228 }
229
bpf_obj_get(const char * pathname)230 int bpf_obj_get(const char *pathname)
231 {
232 union bpf_attr attr;
233
234 bzero(&attr, sizeof(attr));
235 attr.pathname = ptr_to_u64((void *)pathname);
236
237 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
238 }
239
bpf_prog_attach(int prog_fd,int target_fd,enum bpf_attach_type type,unsigned int flags)240 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
241 unsigned int flags)
242 {
243 union bpf_attr attr;
244
245 bzero(&attr, sizeof(attr));
246 attr.target_fd = target_fd;
247 attr.attach_bpf_fd = prog_fd;
248 attr.attach_type = type;
249 attr.attach_flags = flags;
250
251 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
252 }
253
bpf_prog_detach(int target_fd,enum bpf_attach_type type)254 int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
255 {
256 union bpf_attr attr;
257
258 bzero(&attr, sizeof(attr));
259 attr.target_fd = target_fd;
260 attr.attach_type = type;
261
262 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
263 }
264
bpf_prog_test_run(int prog_fd,int repeat,void * data,__u32 size,void * data_out,__u32 * size_out,__u32 * retval,__u32 * duration)265 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
266 void *data_out, __u32 *size_out, __u32 *retval,
267 __u32 *duration)
268 {
269 union bpf_attr attr;
270 int ret;
271
272 bzero(&attr, sizeof(attr));
273 attr.test.prog_fd = prog_fd;
274 attr.test.data_in = ptr_to_u64(data);
275 attr.test.data_out = ptr_to_u64(data_out);
276 attr.test.data_size_in = size;
277 attr.test.repeat = repeat;
278
279 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
280 if (size_out)
281 *size_out = attr.test.data_size_out;
282 if (retval)
283 *retval = attr.test.retval;
284 if (duration)
285 *duration = attr.test.duration;
286 return ret;
287 }
288
bpf_prog_get_next_id(__u32 start_id,__u32 * next_id)289 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
290 {
291 union bpf_attr attr;
292 int err;
293
294 bzero(&attr, sizeof(attr));
295 attr.start_id = start_id;
296
297 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
298 if (!err)
299 *next_id = attr.next_id;
300
301 return err;
302 }
303
bpf_map_get_next_id(__u32 start_id,__u32 * next_id)304 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
305 {
306 union bpf_attr attr;
307 int err;
308
309 bzero(&attr, sizeof(attr));
310 attr.start_id = start_id;
311
312 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
313 if (!err)
314 *next_id = attr.next_id;
315
316 return err;
317 }
318
bpf_prog_get_fd_by_id(__u32 id)319 int bpf_prog_get_fd_by_id(__u32 id)
320 {
321 union bpf_attr attr;
322
323 bzero(&attr, sizeof(attr));
324 attr.prog_id = id;
325
326 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
327 }
328
bpf_map_get_fd_by_id(__u32 id)329 int bpf_map_get_fd_by_id(__u32 id)
330 {
331 union bpf_attr attr;
332
333 bzero(&attr, sizeof(attr));
334 attr.map_id = id;
335
336 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
337 }
338
bpf_obj_get_info_by_fd(int prog_fd,void * info,__u32 * info_len)339 int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
340 {
341 union bpf_attr attr;
342 int err;
343
344 bzero(&attr, sizeof(attr));
345 attr.info.bpf_fd = prog_fd;
346 attr.info.info_len = *info_len;
347 attr.info.info = ptr_to_u64(info);
348
349 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
350 if (!err)
351 *info_len = attr.info.info_len;
352
353 return err;
354 }
355